Scuba diving is a popular recreational activity enjoyed by hundreds of thousands of people across the globe. However, because of the risks associated with scuba diving, one of the fundamental safety rules is that divers should dive with and be in communication with a companion diver, i.e., buddy. The most primitive method of attracting a companion diver's attention when out of visual contact is to bang a hard object, such as a knife, against the diver's air tank. However, this can be inconvenient and requires considerable effort. Furthermore, this method of signaling has a limited range because the ear does not couple reliably to sound waves in water, and other noises, such as the sounds made by a diver's breathing, tend to mask signaling sounds.
A wide variety of underwater communication devices have been proposed and manufactured. However, they generally suffer from the disadvantages of being unwieldy, and difficult to use, having a limited communication range, not specific to (i.e., private between) diver pairs or groups of divers, lacking reliability, or failing to function well.
Therefore it is an object of the present invention to provide an underwater communication system which is compact, easy to operate, specific, reliable, and has an extended communication range.
More particularly, it is an object of the present invention to provide underwater transceivers that communicate using ultrasonic compression waves.
Still more particularly, it is an object of the present invention to provide underwater transceivers that communicate using ultrasonic compression waves which are transmitted omni-directionally.
More particularly, it is an object of the present invention to provide underwater transceivers that communicate using ultrasonic compression waves in an environment which may produce echoes or phase shifts.
It is another object of the present invention to provide underwater transceivers whose components are not susceptible to damage due to water leakage.
More particularly, it is an object of the present invention to provide an underwater transceiver whose components, which include a rechargeable battery, are not susceptible to damage due to water leakage.
Still more particularly, it is an object of the present invention to provide an underwater transceiver whose components, which include a rechargeable battery, are not susceptible to damage due to water leakage, and where the charge level of the battery is ascertainable.
It is another object of the present invention to provide an underwater transceiver whose components are not susceptible to damage due to water leakage, and which is programmable and/or from which dive data can be extracted.
It is another object of the present invention to provide underwater transceivers which have different modes of operation when submerged and when not submerged.
It is another object of the present invention to provide an underwater communication system where divers are informed, visually, audibly and/or through tactile means, that communications have been received by their transceiver or by a companion transceiver.
It is another object of the present invention to provide underwater transceivers which monitor the separation distance between transceivers.
More particularly, it is an object of the present invention to provide underwater transceivers which monitor an inter-transceiver separation distance and inform divers when transceivers are near the limit of their communication range.
It is another object of the present invention to provide underwater transceivers with low power usage.
It is another object of the present invention to provide multiple groups of underwater transceivers where each transceiver within a group communicates over a communication channel used by that group.
And it is an object of the present invention to provide multiple groups of underwater transceivers where each transceiver within a group communicates over a communication channel used by that group, and where public channel communications are received by transceivers in all groups.
It is another object of the present invention to provide an underwater communication system with means for error detection and correction.
It is another object of the present invention to provide an underwater communication system which uses Golay codes.
It is another object of the present invention to provide an underwater communication system which uses binary frequency-shift key modulation.
It is another object of the present invention to provide a method for adapting air-environment lenses for use underwater.
It is another object of the present invention to provide a method for receiving sinusoid-based transmissions having a low signal-to-noise ratio.
It is another object of the present invention to provide an underwater sensing device that is not susceptible to damage due to water leakage into the device.
It is another object of the present invention to provide an underwater sensing device with an internal rechargeable battery that is not susceptible to damage due to water leakage into the device.
It is another object of the present invention to provide an underwater sensing device whose components are not susceptible to damage due to water leakage, and which is programmable and/or from which dive data can be extracted.
These and other objects of the present invention will become more apparent and will be better understood through reference to the subsequent detailed description considered in conjunction with the accompanying drawings.